Synthesis and structural characterization of a superconducting GdSr2RuCu2O8−δ single crystal grown by partial melting

Abstract

We successfully synthesized a superconducting GdSr2RuCu2O8−δ (RuGd-1212) single crystal via the partial melting technique. Structural analysis of this crystal indicated the substitution of Cu and Gd at the Ru and Sr sites, respectively. The disappearance of superconductivity in non-superconducting samples could be attributed to the substitution of Ru in the CuO2 planes and/or Gd at the Sr sites. The distance between the CuO2 planes in the superconducting RuGd-1212 single crystal was shorter, indicating that the valence of Cu in the CuO2 plane had decreased. A superconducting transition with Tc-onset of 23.0 K and Tc-zero of 6.2 K was observed.